The determination of the Al-content in the tetrahedra of framework silicates
Abstract
A method is proposed to calculate the Al-content in the tetrahedra of framework silicates. The method takes into account that: a) when disorder is present, the coordinates of framework atoms, obtained by X-ray or neutron structure refinements, do not correspond to their true positions but to the centre of gravity of more than one position really occupied in the different unit cells: consequently the measured T – O distance is shorter than the true T – O distance and the Al-content is underestimated; b) the Si – O and AI – O distances are not constants but decrease with the increasing of the T – O – T angle, so that the calculated Al-content is normally overestimated for low T – O – T angles and underestimated for large T – O – T angles. A computer program which calculates the Si/Al ratio for each tetrahedron has been written.
Artikel in diesem Heft
- Structural and chemical varieties of dioptase, Cu6[Si6O18] · 6 H2O*
- Crystal chemistry of iron in natural and in synthetic braunites Mn2+(Mn3 + ,Fe3+)6O8/SiO4
- Hyperoctahedral groups, wreath products, and a general Weyl's recipe
- The determination of the Al-content in the tetrahedra of framework silicates
- The crystal structure of natural monoclinic analcime (NaAlSi2O6 · H2O)
- The Patterson function of superstructures: anomalous dispersion effect
- Considerations on the partial Patterson function of superstructures
- Molecular and crystal structure of {cpCo[P(O)(OC2H5)2l3}2Hg
- Low-temperature structural distortion in CuS
- The solid phases of sulphur hexafluoride by powder neutron diffraction
- Complexe 1/1 entre le chlorodiethylamino phenyl iminophosphorane et le trichlorure d'aluminum. Determination structurale
- Refinement of the crystal structures of RbClO4 and CsClO4
Artikel in diesem Heft
- Structural and chemical varieties of dioptase, Cu6[Si6O18] · 6 H2O*
- Crystal chemistry of iron in natural and in synthetic braunites Mn2+(Mn3 + ,Fe3+)6O8/SiO4
- Hyperoctahedral groups, wreath products, and a general Weyl's recipe
- The determination of the Al-content in the tetrahedra of framework silicates
- The crystal structure of natural monoclinic analcime (NaAlSi2O6 · H2O)
- The Patterson function of superstructures: anomalous dispersion effect
- Considerations on the partial Patterson function of superstructures
- Molecular and crystal structure of {cpCo[P(O)(OC2H5)2l3}2Hg
- Low-temperature structural distortion in CuS
- The solid phases of sulphur hexafluoride by powder neutron diffraction
- Complexe 1/1 entre le chlorodiethylamino phenyl iminophosphorane et le trichlorure d'aluminum. Determination structurale
- Refinement of the crystal structures of RbClO4 and CsClO4
